The main accuser in Bill Cosby's trial gave emotional testimony in court Tuesday, delivering her first public remarks about the night he allegedly drugged and sexually assaulted her 13 years ago.

In one of America's biggest celebrity trials in years, the disgraced 79-year-old megastar faces three counts of aggravated indecent assault, which each carry a maximum sentence of 10 years in jail and a $25,000 fine.

Around 60 women have publicly accused the Emmy-winning television star and comedian of being a serial sexual predator for decades, ending his career and leaving him isolated by friends and celebrities.

But his fate rests on the allegations of just one, Andrea Constand, about an encounter at his Philadelphia mansion in January 2004.

It is the only criminal case against him, as most of the alleged abuse happened too long ago to prosecute.

"I wanted it to stop," 44-year-old Constand told the second day of the trial in Norristown, Pennsylvania about the evening in question.

Constand's testimony is central to the case against the star of "The Cosby Show," one of the most popular shows in the history of television. Legal experts say the case will essentially boil down to her word against his.

She says the pioneering black comedian, whom she considered a mentor, gave her three pills and wine before sexually assaulting her on his couch after she sought his advice about moving to Canada and switching careers.

The then-30-year-old director of women's basketball at Temple University -- where Cosby was serving on the board of trustees -- said she had asked the television star if the pills were herbal, and that he indicated they were.

"I said I trust you," she recalled saying at the time.

- 'Humiliated' -
About half an hour later, Constand said, she had trouble talking and difficulty moving and was suffering double vision. After briefly losing consciousness, she regained it as Cosby was touching her private parts, she testified.

"In my head, I was trying to get my hands to move, get my legs to move, but I was frozen and those messages didn't get there," she said, her voice breaking.

Tuesday marked her first public appearance since she submitted to a deposition in December 2005, after waiting a year to report the alleged assault.

She initially settled the case with a civil suit in 2006, but prosecutors in Montgomery County re-opened it in 2015, saying new evidence had come to light.

Smiling, dressed in a pale blue jacket and a white top, she answered initial questions from Assistant District Attorney Kristen Feden calmly but her demeanor changed when the testimony switched to the alleged assault.

"I felt really humiliated and I was really confused," she said.

Cosby maintains only that he gave Constand the antihistamine Benadryl to relieve stress, insists their sexual relations were consensual and accuses her of lying.

Cosby, for years feted by millions as "America's Dad" for his role as a lovable obstetrician and father on "The Cosby Show," says he is now legally blind.

- 'Mentor' -
Constand testified that on a previous evening at his home, the actor had tried to unfasten her pants. She said she moved away, told him that she was not interested in a physical relationship and left the house.

"He was somebody I trusted, a mentor and somewhat of an older figure to me," she explained to the seven-man, five-woman jury.

Constand said that when she later called Cosby to ask why he had given her the pills he replied: "I thought you had an orgasm, didn't you?"

After Constand told her mother and her mother challenged Cosby, the actor told her the same thing -- "that he felt I had an orgasm" -- she testified.

Asked by the prosecution why she waited to report the incident, Constand replied that she did so due to his status as a trustee, an alumnus and a benefactor of athletics programs.

The defense has argued that Cosby's infidelity to his wife made him "vulnerable" to accusations and has sought to undermine Constand's credibility, portraying their relationship as consensual, with many meetings and phone calls.

In cross-examination, defense lawyer Angela Agrusa sought to expose inconsistencies in Constand's testimony, highlighting an initial declaration to police that she had never otherwise been alone with Cosby.

"There was a lot of confusion putting the dates and the facts together," Constand replied.

Cross-examination is due to continue on Wednesday. The jury will be sequestered for the duration of the trial, which is expected to last about two weeks.